1. Field of the Invention
The present invention relates generally to a recording medium loading device, and more particularly, to a recording medium loading device that prevents a disk cartridge containing a recording medium from being improperly inserted into a disk cartridge holder.
2. Description of the Related Art
FIGS. 1A, 1B, 1C and 1D are diagrams for the purpose of explaining a conventional mechanism for preventing a disk cartridge from being improperly inserted into a holder, hereinafter referred to as a prevent mechanism.
The conventional recording medium loading device prevent mechanism, as shown for example in FIG. 1A, has a prevent tab 2 provided on a left interior wall of a holder 1 and a shutter drive tab 3 provided on a right interior wall of the holder 1, with the shutter drive tab 3 being positioned closer to an insertion opening 4 side than the prevent tab 2.
A disk cartridge C in which is contained a disk-like recording medium D has a shutter 6 for opening and closing an opening 5 for the purpose of exposing the disk-like recording medium D, and a shutter retaining member (not shown in the diagram) that retains the shutter 6 at a closed position. By contacting the shutter drive tab 3, the shutter retaining member releases its retention, after which the shutter drive tab 3 moves relative to the shutter 6 upon the insertion of the disk cartridge C, moving the shutter 6 to an open position.
The disk cartridge C is inserted into the holder 1 so that the shutter 6 is on the right side. In this aspect, the disk cartridge C has a groove 7 formed on a left front side thereof for accommodating the prevent tab 2 and another groove 8 formed on a right front side thereof for accommodating the shutter drive tab 6.
Additionally, the disk cartridge C has a width slightly smaller than a width L1 of the holder 1. A length L2 of the disk cartridge C is set to be slightly smaller than the holder 1 width L1, so that L1 greater than L2.
Additionally, a length L4 from a back surface of the holder 1 to the prevent tab 2 is formed so as to be slightly shorter than a length L3 of the groove 7 in a direction of insertion, so that L3 greater than L4.
As shown in FIG. 1B, when the disk cartridge C is inserted into the holder 1 properly, that is, in the proper direction, the prevent tab 2 advances into the groove 7 of the disk cartridge C and insertion is permitted. Additionally, the shutter drive tab 3 advances into the groove 8 of the disk cartridge C and releases the retention of the shutter 6, after which the shutter 6 begins to open as the disk cartridge C is inserted.
When the disk cartridge C reaches this position, a loading mechanism motor switch (not shown in the diagram) detects same and the loading mechanism drive motor (not shown in the diagram) is activated.
As shown in FIG. 1C, when the loading mechanism is activated and the disk cartridge C is retracted into the holder 1, the shutter 6 opens completely and the retraction of the disk cartridge C is completed, that is, the disk cartridge is loaded.
As shown in FIG. 1D, if for example the disk cartridge C is incorrectly inserted into the holder 1 so that the shutter 6 is positioned at the front edge thereof, the prevent tab 2 contacts an edge member of the disk cartridge C and makes insertion impossible. Additionally, the shutter drive tab 3 contacts a side surface of the disk cartridge C. As a result, the disk cartridge C is inserted in a state of displacement to the left within the holder 1 and the front edge securely contacts the prevent tab 2, thereby preventing insertion.
However, a disadvantage of the conventional recording medium loading device described above is that the positioning of the prevent tab 2 is restricted by the groove 7 of the disk cartridge C, that is, L4 less than L3, and, as a result, an improper insertion of the disk cartridge C is detected too late. That is, a distance L5 from the back wall of the holder to the front edge of the cartridge contacted by the prevent tab 2 must be less than the distance L4 because of the presence of the groove 7 on the disk cartridge C for accommodating the prevent tab 2.
Moreover, in order to prevent the loading mechanism motor described above from being activated and an incorrectly inserted disk cartridge C from being retracted into the holder 1, a position at which the cartridge begins to be retracted must be further back from the insertion opening than the position at which an incorrect insertion is detected. In other words, a distance L6 from the back wall of the holder 1 to the position at which the cartridge begins to be retracted must be less than the distance L5 from the back wall of the holder to the front edge of the cartridge contacted by the prevent tab 2, which, as noted above, must be less than the distance L4, such that L6 less than L5 less than L4.
As a result, with the conventional recording medium loading device there is the disadvantage of being unable to increase the disk cartridge C retraction distance.
Additionally, because the distance the disk cartridge C is retracted by the retraction mechanism cannot be increased, a distance L7 from the disk cartridge C insertion opening at the front of the disk drive to the front edge of the disk cartridge C when the disk cartridge C is loaded is strictly limited, so that L7 less than L2+L6.
As a consequence of these restrictions design flexibility as a whole is limited. Specifically, the position of the guide shafts that determine the location of the optical pick-up to be described later is strictly limited by these above-described dimensional restrictions and cannot be located freely, thus limiting the degree to which the design of the disk drive overall may be made more efficient and more compact.
Additionally, because the distance the disk cartridge C is retracted by the retraction mechanism cannot be increased, the shutter 6 opens when the disk is inserted manually and the shutter 6 retention release and opening operations triggered by the contacting of the shutter drive tab 3 are transmitted to the hand of the operator, resulting in an unpleasant sensation.
Accordingly, it is an object of the present invention to provide an improved and useful recording medium loading device in which the above-described disadvantages are eliminated.
The above-described object of the present invention is achieved by a recording medium loading device comprising:
a holder into which a cartridge containing a disk-like recording medium is inserted from a predetermined side;
a cartridge retraction mechanism that retracts the cartridge when the cartridge is inserted to an insertion detection position inside the holder; and
a prevent mechanism, the prevent mechanism being moved in a direction of insertion of the cartridge by the cartridge retraction mechanism when the cartridge is inserted from the predetermined side.
According to the invention described above, detection of improper insertion takes place sooner and at the same time cartridge retraction can take place sooner as well. As a result, the distance of retraction from a position at which cartridge retraction commences to a position at which retraction is completed can be lengthened.
The above-described object of the present invention is also achieved by the recording medium loading device described above, further comprising:
detecting means detecting insertion of the recording medium cartridge to the insertion detection position and emitting a signal; and
driving means driving the cartridge retraction mechanism and the prevent tab in response to the signal emitted by the detecting means indicating that the recording medium cartridge is inserted to the insertion detection position and displacing the cartridge retraction mechanism and the prevent tab in a direction of insertion of the recording medium cartridge.
According to the invention described above, retraction of the cartridge is performed automatically after the cartridge has reached a position at which manual insertion is completed and, at the same time, the cartridge shutter can be opened in the process of retracting the cartridge.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.